Alarm booth

ABSTRACT

A booth having an entrance door and being otherwise totally enclosed with a fire alarm call box mounted inside to one wall. Electrical switches actuated by weight on the booth floor and closing of the booth door cause the booth door to be automatically locked for a pre-set time interval upon the ringing of the fire alarm. After elapse of the pre-set time interval, unless the door lock has already been deactuated by fire or police department personnel arriving at the booth, the door automatically unlocks to release the person inside. Means are described to insure door unlocking in the event of power or component failure, and a local alarm and system test means are provided. Under conditions of no power failure, the booth door must be closed with the alarm sender inside the booth or the fire alarm cannot be actuated.

United States Patent [191 Mann et al.

[451 May 27, 1975 ALARM BOOTH [75] Inventors: Yale M. Mann, Rydal; Walter B. Udell, Melrose Park, both of Pa.

[73] Assignee: Yale M. Mann, Rydal, Pa.

[22] Filed: June 28, 1973 [2l] Appl. No.: 374,399

l,267,l65 5/l9l8 Arnavas 340/304 Primary ExaminerThomas B. Habecker Attorney, Agent, or Firm-Edelson and Udell [57] ABSTRACT A booth having an entrance door and being otherwise totally enclosed with a fire alarm call box mounted inside to one wall. Electrical switches actuated by weight on the booth floor and closing of the booth door cause the booth door to be automatically locked for a pre-set time interval upon the ringing of the fire alarm. After elapse of the pre-set time interval, unless the door lock has already been deactuated by fire or police department personnel arriving at the booth, the door automatically unlocks to release the person inside. Means are described to insure door unlocking in the event of power or component failure, and a local alarm and system test means are provided. Under conditions of no power failure, the booth door must be closed with the alarm sender inside the booth or the fire alarm cannot be actuated.

6 Claims, 8 Drawing Figures ALARM BOOTH This invention relates generally to alarm systems, and more particularly is directed toward fire alarm systems in which a known problem is that of the sending of false alarms resulting in the unnecessary dispatch of fire fighting equipment attended by the high costs incurred and the unavailability of the equipment at other loca tions where a real fire may require its presence.

Under present circumstances. fire alarm call boxes are located at various points in an open environment such that an alarm may be rung in by unknown persons who then quickly depart from the scene and are not apprehendable. The present invention is directed toward changing the environment of the fire alarm call box so that a person turning in a fire alarm must of necessity remain at the fire alarm call box for a predetermined minimum length of time which is normally sufficient for fire fighting equipment or a police car to arrive at the location of the fire alarm call box for instruction as to the location of the fire.

This objective is accomplished by locating the fire alarm call box inside a booth which is so equiped that under normal circumstances it is necessary for a person wishing to call in a fire alarm to first step inside of the booth and close the door. Only then can the fire alarm be actuated, and simultaneously with such alarm actuation. the door to the fire alarm booth becomes immediately locked and a local alarm is actuated at the booth to call attention to the fact that an alarm has been rung in. The door of the booth remains locked for a predetermined length of time and is then automatically un locked to release the person in the booth.

The automatic unlocking of the booth door is an important aspect of the invention and provides two func tions. Firstly. it is unlikely that anyone would be willing to enter a booth to turn in a fire alarm in the case of a real fire if the person understood that indefinite detention inside the booth would be the consequence. Moreover. it would always be possible that a malfunction in the fire alarm signal equipment might occur so that no alarm in fact was rung into the central control point and there would be no knowledge whatever that someone had been locked into a booth at some particular location. The possible adverse legal and medical consequences of such an event are apparent and constitute the major reasons why indefinite detention type alarm booths have never gained acceptance despite the fact that such a concept has been put forth for almost a century.

Additionally. the present invention provides an alarm booth door locking mechanism which while power actuated is capable of automatic unlocking in the event that an electrical power failure should occur after the locking mechanism had been actuated, so that under no circumstances may a person be detained in the alarm booth more than a pre-detcrmined length of time. Once it is understood by the general public that release from the alarm booth is a certainty after a predetermined time interval. as for example five or six minutes there will be little reluctance for members of the public to turn in a tire alarm when necessary. On the other hand, with the foreknowledge that temporary detention in the alarm booth is a certainty. there will be a great deterent effect exerted upon those persons who are prone to turn in false alarms since they will under stand that they would necessarily be apprehended and subjected to the penalties of the law for their action.

It is a principal object of this invention to provide a novel alarm booth as aforesaid for temporarily detaining a person who causes an alarm to be rung so that the proper authorities have time to reach the alarm booth before release of the person detained there.

Another object of the invention is to provide a novel alarm booth in which it is a necessary pre-condition to the sending of an alarm that a person enter the booth and completely close the booth door.

Yet another object of the invention is to provide a novel fire alarm booth as aforesaid wherein in the event of an electrical power failure the detention mechanisms associated with the alarm are rendered inoperative and the alarm system remains operative so that an alarm may still be called in.

The foregoing and other objects of the invention will become clear from a reading of the following specification in conjunction with an examination of the appended drawings. wherein:

FIG. 1 is a front view of an alarm booth according to the invention within which is mounted a fire alarm call box;

FIG. 2 is a side view of the alarm booth shown in FIG.

FIG. 3 is a view similar to FIG. 2 but with portions of the booth structure sectioned away to disclose some of the operative mechanism;

FIG. 4 shows an electromechanical door lock and re lease mechanism;

FIG. 5 is a view of the door lock mechanism shown in FIG. 4 as would be seen when viewed along the line 55 thereof;

FIG. 6 is a schematic diagram of a control system for the alarm booth according to the invention;

FIG. 7 is a schematic diagram of a modified form of control system according to the invention; and

FIG. 8 is a schematic diagram of a third control system according to the invention.

In the several figures, like elements are denoted by like reference characters.

Turning now to the figures. and considering first FIGS. I, 2 and 3, there is seen a fire alarm booth designated generally as 10 having a front door 11, side walls 12, a back wall 13, a support base 14 and closed top 15. Mounted inside the booth to the back wall 13 is a conventional type of fire alarm call box designated generally as 16. The booth door 11 has mounted within it a lock mechanism 17 which includes a shiftable bolt 18 that is seatable when extended in an appropriate cooperating recess in the door jamb 19 of the booth 10. Also associated with the door jamb 19 is a door actuated electrical switch 20 which is operated in one way when the door I l is opened and is operated in a different way when the door 11 is closed.

Similarly, as best seen in FIG. 3, an electrical switch 2I is carried in the booth support base 14 and is actuated by the weight ofa person stepping inside the booth upon the vertically deflectable booth floor 22. The movement of the floor 22 to cause actuation of the floor switch 21 may be made so slight as to be substantially imperceptible to a person entering the booth. Carried by the booth top is a local alarm 23 which may be either an audible or visual alarm or both and which is rendered operative when the fire alarm is rung The fire alarm call box I6 is provided with an alarm actuating handle 24 which when pulled downward causes the fire alarm transmitter inside the box to send out a coded signal designating which particular alarm box the incoming call emanates from. The alarm transmitter is designated in the schematic showing of FIG. 6 as 25. and is caused to transmit when the mechanically linked vertically reciprocable operator 26 is moved downward by actuation of the alarm handle 24. The mechanism is such that the operator 26 remains in its downward position once it has been actuated for a pre-determined length of time sufficient to enable the alarm transmitter 25 to transmit several cycles of its coded message, the operator 26 then automatically moving upward to its unactuated position.

The schematic of FIG. 6 discloses a circuit which provides a fail safe type of fire alarm transmission together with automatic release of the alarm sender from the alarm booth after a pre-determined time interval, and draws no electrical current until such time as an alarm is rung. Physically engaged with the operator 26 is the actuating arm 27 of a switch assembly 28 having two normally closed switches 29 and 30 which are held in their open circuit condition against the bias of loading spring 31 by virtue of engagement of the actuating arm 27 with the operator 26. When the operator 26 moves downward in order to transmit an alarm, the spring 31 of switch assembly 28 drives the actuating arm 27 downward to thereby sequentially close the switches 29 and 30 with the switch 30 being the first to close.

in series with the switch 29 of switch assembly 28 are the normally opened switches a and 21a of the door switch assembly 20 and floor switch assembly 21 re spectively, and in series circuit with the switch 30 of switch assembly 28 are the normally open switches 20b and 21b of the door switch assembly 20 and floor as sembly switch 21 respectively. If desired, the floor switch 21 may be omitted. Switch 200 is also connected to one terminal 32 ofa source of electrical energy such as the normally available 120 volt alternating current of most municipal power supplies, the other terminal of the power supply being that designated as 33. Switch 20b of door switch assembly 20 is connected to one terminal 34 of the source of electrical power used to energize the tire alarm transmitter 25, and which is usually an independent source of power maintained by the fire department and which will remain operative even in the event of a failure of the normal municipal power supply. the other terminal of the alarm transmitter power supply being designated 35.

An interference member 36 is so positioned with respect to the vertically shiftable operator 26 that the operator 26 cannot be pulled downward to the bottom of its travel position in order to actuate the alarm transmitter unless the interference member 36 is physically shifted to an unobstructing position. The interference member 36 is pivotable about pivot 37 against the action of spring 38 so that its upper end moves to the right into a position of non-interference with operator 26 by energization of solenoid 39 which pulls the solenoid plunger 40 to the left. Energization of the solenoid 39 to shift the interference member 36 can only occur when both the door switch 20 and the floor switch 21 have been closed and the alarm actuating handle 24 has thereafter been pulled downward.

The interference member 36 is so positioned with respect to the operator 26 that limited downward movement of the operator 26 can take place before it encounters the interference member. To this end. switch 30 of switch assembly 28 is arranged to close within the range of limited downward movement of the operator 26 so that a completed electrical circuit from the power source 34-35 through solenoid 39 is established through closed switches 20!). 21b, and 30. Energization of solenoid 39 pivots the interference member 36 to the right to permit continued downward movement of the operator 26 to the point where the alarm transmitter 25 is tripped. The electrical circuit for the alarm transmitter 25 is also completed through switches 20b and 2 lb.

In order for the foregoing sequence to occur so that an alarm is transmitted. it is clear that floor switch 21 and door switch 20 must both have been closed. Closure of floor switch 21 occurs when a person wishing to ring in an alarm walks into the booth and exerts pressure downward on the deflectable booth floor 22 by virtue of the person's normal body weight. The alarm at this point can still not be rung because the door of the booth must also be closed in order to close door switch 20. Consequently, not only must a person walk into the booth but must positively close the door in order to establish the conditions which will permit the alarm transmitter 25 to be activated by permitting the interference member 36 to be moved out of the way of the operator 26.

As operator 26 is moved downward to first close switch 30 it will be observed that this switch closing action occurs by movement of the switch actuating arm 27 downward under the influence of spring 31. The action of spring 31 continues the downward movement of actuating arm 27 so that switch 29 closes just prior to or simultaneously with the actuation of the alarm transmitter 25. Since door switch 20 and floor switch 21 are already closed, power flows from source 32-33 through switches 20a, 21a and 29, through normally closed key switch 41, through door lock solenoid 42, and through relay coil 43 and local alarm 23 via a set of normally closed relay contacts 44.

Energization of the door lock solenoid shifts the solenoid plunger 45 to the right thereby causing door lock bolt 18 to be engaged in the bolt opening of door jamb 19, as shown in dotted line, and simultaneously winds a mechanical timer designated generally as 46. The mechanical timer 46 holds the solenoid plunger in its bolt locking position against the urging of a plunger return spring (not shown in FIG. 6) until such time as the timer has timed out and thereby releases the solenoid plunger 45 for retraction of the door locking bolt 18 provided that the door lock solenoid 42 has previously been deenergized.

Door lock solenoid 42 will normally have previously been de-energized because alarm transmitter operator 26 only remains in its downward shifted actuating position for a preset length of time sufficient for the alarm transmitter 25 to transmit several cycles of its identifying code, the operator 26 thereafter returning to its upward unactuated position and thereby shifting switch actuating arm 27 upward to open switches 29 and 30. The opening of switch circuit 29 of course de-energizes door lock solenoid 42. However, the locking bolt 18 is not at that time retracted because the timer 46 will not have as yet timed out. Generally, the time set for the mechanical timer 46 will be a time just somewhat longer than the time normally required for police or fire department personnel to reach the scene of the alarm boothv Energization of the relay coil 43 causes the normally open relay contacts 47 to close prior to the opening of normally closed relay contacts 44 to thereby establish a holding circuit for relay coil 43 from the source of electrical power 32-33 via closed door switch circuit a. The initial closing of switch 29 and the establishment of the holding circuit by relay 43 energizes the local alarm 23 which may, as previously described, be an audible or visual alarm such as a siren or a flashing light to call attention to the fact that an alarm has been rung in from that particular alarm booth and that someone is presently inside the booth. The holding circuit for the local alarm 23 which is established through relay contacts 47 is necessary in order to maintain the local alarm in a functioning state at such time as switch 29 opens, and to maintain the alarm in operation continuously thereafter so long as the door of the alarm booth is closed.

In due course, personnel of either the fire department or the police department arrive at the booth and can release the alarm sender from the booth by means of a key release 48 which discharges the mechanical timer 46 of its bolt retracting function. In the event that some malfunction occurs in the alarm transmitter so that an alarm is in fact not received at the alarm receiving center, and no one is dispatched to the alarm booth, or if for any other reason the fire or police personnel do not reach the alarm booth before a pre-determined time for which the mechanical timer 46 has been set. as for example 6 or 8 minutes, then the timer 46 times out and releases the solenoid plunger retraction spring so that the door locking bolt 18 is automatically retracted and the booth door 11 is unlocked to permit the alarm sender to leave the booth. As soon as the booth door is opened, switch 20a of course opens and breaks the holding circuit to relay 43 which immediately drops out and shuts off the local alarm 23.

The normally closed key switch 41 is provided for testing the alarm transmitter 25 without actuating the door lock mechanism or the local alarm 23. This is achieved simply by opening the switch 41 so that when operator 26 is shifted downward to close switches 29 and 30, there is no power transmission through switch circuit 29 to any of the door lock solenoid 42, local alarm 23 and relay coil 43. When the alarm transmitter has been checked out. the switch 41 is manually re stored to its closed condition and the system is rendered again functional.

Also provided is a normally open key switch 49 which connects the power source 32-33 directly to door lock solenoid 42 and relay coil 43, by-passing switch assembly 28 altogether. Switch 49 when closed tests the operability of the door lock circuit and the local alarm 23 without transmitting a tire alarm into the alarm receiving center. When the test has been satisfactorily completed, the switch 49 is restored to its open condition.

Finally, an electrical surge protection mechanism 50 is provided at the power supply terminals 32-33 to prevent overvoltage conditions on the line, such as lightning strokes, from rendering the system inoperative.

Any suitable mechanical timer 46 may be used, and one particular form of such a device is shown in FIGS. 4 and 5 to which attention should now be directed. As best seen in FIG. 4, the solenoid plunger 45 is disposed through the door lock solenoid coil 42 and is spring loaded by spring 51 to be in a normally retracted position. The left end of the plunger 45 is provided with teeth to form a rack 52 engaged with a pinion gear 53. The pinion gear 53 is connected through a one way drive mechanism 54, seen in FIG. 5, to a driving gear 55 which latter is in turn meshed with a timer gear 56 spring loaded by spring mechanism 57. The mechanism 54 prevents reverse drive of gear 53 by gear 55. Fixed to and extending from the side of gear 56 is a pin 58 which is normally engaged with one arm of an L-shaped plunger 59, the other arm of the plunger being loaded by a spring in such direction as to normally drive the plunger 59 against the rack of the solenoid plunger 45.

In the timed out state of the timer 46 as shown in FIG. 4, the pin 58 occupies a position in which the plunger 59 is held retracted away from the rack 52 against the bias of spring 60 so that the solenoid spring 51 is enabled to retract the solenoid plunger 45. When however the door lock solenoid coil 42 is energized, the solenoid plunger 45 is immediately shifted to the right causing the rack 52 to rotate pinion gear 53 and driving gear 55 in the direction shown through the one way clutch 54 to thereby rotate the spring loaded timer gear 56 in such a direction, as shown by the arrow. to cause pin 58 to move around the dotted circle to a position 58' and hence to be disengaged from the plunger 59. The loading spring 60 causes the plunger 59 to move upward into a position behind the end of rack 52 which has moved to the right so that the rack 52 cannot return to the left while the plunger 59 is in its obstructing position.

De-energization of the door lock solenoid 42 merely allows the spring 51 to shift the solenoid plunger 45 just slightly to the left until it engages the obstructing plunger 59. it thus being restrained from further unlocking movement of the bolt 18. As the timing spring mechanism 57 counter-rotates the timer gear 56, the pin 58 counter-rotates about the dotted circle toward its initial position, and the gear 55 which is engaged with the timer gear 56 spins freely in disengagement from the rack gear 53 by means of the one way clutch 54. When the pin 58 counter-rotates to a position where it engages the arm of plunger 59 and continues its counter-movement towards its initial rest position. it carries plunger 59 with it against the bias of spring 60 until the end of the plunger 59 moves outward from its obstructing position behind the rack 52 and permits the spring 51 to then fully retract the solenoid plunger 45 and locking bolt 18.

If the fire or police personnel arrive at the booth before the timer has timed out, they may unlock the door immediately by means of the key release 48 which merely retracts the plunger 59 irrespective of the particular position of the pin 58 at that time. Of course. retraction of the plunger 59 will, as previously described, free the rack 52 and allow retraction of the locking bolt 18 by means of the solenoid spring 51.

The system shown and described in connection with FIG. 6 is a fail safe system insofar as a failure of the municipal power supply system 32-33 does not prevent a fire alarm from being transmitted since the separately maintained alarm circuit power system 34-35 will still be functional. However, while failure of the switches 20h, 21b and 30 is extremely unlikely, nevertheless. there is a possibility that a failure could ultimately occur in the solenoid coil 39 so that the availability of power in circuit 34-35 would still not permit an alarm to be transmitted because a failure of the solenoid 39 would leave the interference member 36 in its interfering obstructing position with respect to the operator 26 and no alarm could be transmitted. A somewhat moditied fail safe system which avoids this possibility is illustrated in the circuit of FIG. 7 to which attention should now be directed.

The fundamental philosophical difference between the circuits of HGV 7 and FIG. 6 is that in the circuit of FIG. 7 the interference member 36 is normally biased to an unobstructing position by the action of spring 61 and is held in its interfering position only so long as solenoid coil 62 is energized to pivot the interference member 36 into obstruction position by overcoming the retracting spring bias of spring 6l. Such a system of course requires a constant electrical current drain of magnitude sufficient to energize solenoid coil 62. and this requirement dictates a modification of the door switch and the floor switch to the configuration illustrated in FIG. 7 in which the door switch is designated as 200 and the floor switch as 210.

The door and floor switches 200 and 210 respectively include normally open switches a and 21a which are identical to the same numbered switches in the door and floor switches 20 and 21 shown in FIG. 6, and in fact these switch circuits function in the same manner. However. in place of switches 20b and 21b of the door and floor switch assemblies 20 and 21 of FIG. 6, the door switch assembly 200 and floor switch assembly 210 of FIG. 7 are respectively provided with normally closed switches 200b and 2l0b. One side of each of the switches 20Gb and 21Gb is connected to terminal 32 of the power source while the remaining sides of each of the switches 20017 and 2l0b are connected in parallel and to one end of the solenoid coil 62, the other end of solenoid coil 62 being returned to the other terminal 33 of the power supply.

This circuit modification permits energization of the solenoid coil 62 from the power supply 32-33 through switches 200b and 210 so long as the alarm booth door is open and there is no one inside the booth standing on the booth floor. When a person enters the booth switch 21% automatically opens but solenoid 62 remains energized through the parallel switch 200!) of the door circuitv When the person who has entered the booth then closes the door thereby opening switch 200/; the current flow to solenoid coil 62 is interrupted and the solenoid is de-energized permitting spring 61 to shift the interference member 36 into an unobstructing position so that the alarm may now be rung in.

If the alarm is in fact struck by moving the operator 26 downward then the door to the booth is immediately locked and the local alarm 23 is actuated in exactly the manner previously described in connection with the showing of FIG. 6. it should be noted that the alarm transmitter is directly connected to its normal power source 34-35 without any intervening switch mechanisms as is for example the case in the circuit of FIG. 6. Accordingly, the circuit of FIG. 7 is usable with any presently existing alarm system and requires no modification whatcver. all of the additional elements shown in FIG. 7 constituting peripheral equipment.

There is additionally shown in FIG. 7 a switch assembly 63 having a switch 64 normally closed by a spring 65 and which in fact is so closed when the interference member 36 has been moved to its non-interfering position. However, when the interference member 36 is in its operator obstructing position as shown an actuating arm 66 causes the switch 64 to be opened against the bias of spring 65. One side of the switch 64 is connected to terminal 32 of the power supply while the other side ofthc switch 64 is connected to switch 29 so that the switch 63 when closed effectively by-passes the door and floor switches 200 and 210, and the switch 63 actuates the local alarm 23 in the event that an alarm is struck with power available from the power source 32-33 in the circumstance where the interference solenoid 62 fails.

In such circumstance, failure of the solenoid 62 causes the interference member 36 to be retracted even though the alarm booth door is opened and the floor switch has not been actuated. If the alarm is pulled, power is transmitted from the power source 32-33 through now closed switch 63 and the closed switch circuit 29 to the door lock and local alarm circuits. The door lock circuit will of course actuate the locking bolt 18 although the door will still be open and will therefore be ineffective. but the alarm 23 will be actuated and call attention to the malfunctioning state of the alarm booth mechanism.

FIG. 8 illustrates a third control circuit for the alarm booth according to the invention which is similar to the circuit of HO. 6 in that the local alarm actuation is identical, and the operation of the interference member system is also identical excepting that energization for the solenoid coil 39 is taken from the power supply 32-33 instead of from the fire alarm transmitter power circuit 34-35. Similarly, the door switch assembly 20 and floor switch assembly 2] shown in FlG. 6 have been simplified to single switches of the normally open type and previously described as the switches 20a and 21a.

The main difference in the circuit of FIG. 8 is in the door lock mechanism in that instead of the spring re turn solenoid 42 utilized in the circuit of HG. 6. a two coil solenoid 67 is provided in which one coil 68 is utilized when energized to open the door lock by retract ing the bolt 18 whereas the second coil 69 is utilized when energized to lock the door by shifting the bolt 18 into locking engagement with the door jamb 19. The two coil solenoid 67 is controlled by a time delay relay 70 and a control switch 71 which is actuated by the operator 26 by means of actuating arm 72 and spring 73 in the same manner as the switch 28 is actuated in the circuit of FIG. 6, the difference being that the circuit contact arrangement of control switch 71 is different from that of the control switch 28 shown in FIG. 6.

The control switch 71 has a power input contact 74 and three output contacts 75, 76 and 77 which latter are successively interconnected by means of a slider contact 78. Switch output contact is connected to a normally closed switch 79 of time delay relay 70, which switch 79 connects to the lock opening coil 68 of the two coil solenoid 67. Accordingly, when time delay relay switch 79 is in its normally closed position, as shown. the booth door will be unlocked even when a person is standing inside the booth and has closed the booth door.

When the person in the booth starts to turn in an alarm by pulling down the alarm actuating handle 24 to shift the operator 26 downward toward the interference member 36 the first thing which occurs is that the slider contact 78 moves downward to connect switch contact 74 to both switch contact 75 and 76 and thereby cause the interference member 36 to be moved aside in preparation for striking of the alarm. Continued downward movement of slider contact 78 interconnects switch contact 74 with output contacts 76 and 77 while at the same time disengaging from contact 75 so that the lock opening coil 68 is de-energized and inoperative. Continued contact of the slider 78 with output contact 76 maintains the interference member in its non-interfering position while the engagement with contact 77 causes timer reset mechanism 80 to open switch 79 and set the timer 81 to the preset time interval after which, when the timer times out, the switch 79 will be closed.

Energization of output contact 77 also energizes solenoid lock closing coil 69 via normally closed key switch 41 to thereby throw the bolt 18 into locked position, and simultaneously energizes relay coil 43 in the previously described manner to actuate the local alarm 23. Accordingly, the alarm transmitter transmits its coded signal while the local alarm operates continuously and the booth door is locked for the predetermined time interval. When the alarm transmitter 25 has completed its transmission cycle and the operator 26 shifts upward, the contact slider 78 is moved upward against the bias of spring 73 to the position shown in FIG. 8. When thereafter, the timer 81 times out and closes switch 79, lock opening coil 68 of two coil solenoid 67 will thereupon be energized and unlock the alarm booth door. The locking bolt mechanism may of course also be provided with a mechanical release mechanism indicated at 82 which is operable from the outside of the booth by someone in possession of an appropriate key.

Additionally provided for testing purposes is a center-open key switch 83 having its pole connected to terminal 32 of the power source and which is utilizable to check the actuation of the local alarm 23 and the door locking and unlocking circuit mechanism without transmitting a fire alarm by first opening the switch 41 in the manner previously described. Movement of the pole of switch 83 downward to contact 84 energizes lock opening coil 68 while movement of the pole of switch 83 to contact 85 energizes the lock closing coil 69 and the local alarm circuit.

In the event that the power available from the fire alarm power system circuit 3435 is adequate to operate all of the equipment associated with the alarm booth multiplied by the number of the alarm booths in the system, then the power systems can be combined by connecting together power system terminals 33 and 35, and connecting power terminal 34 of the alarm system either to power terminal 32 or to a selected control point in the system. In the circuits of FIGS. 7 and 8 this could be for example the output contact of floor switch 210 and the equivalent in the circuit of FIG. 6.

Having now described the invention in connection with particularly illustrated embodiments thereof, various modifications and variations of the invention may now occur from time to time to those persons normally skilled in the art without departing from the essential scope or spirit of the invention, and accordingly it is intended to claim the same broadly as well as specifically as indicated by the appended claims.

What is claimed is:

1. A personnel detention system for holding captive a person who actuates an alarm circuit, comprising in combination,

a. a primary alarm mechanism having an actuator,

b. an enclosure within which said primary alarm mechanism is mounted, said enclosure having a door through which a person desiring to actuate said alarm may pass, and said enclosure having no other means of ingress or egress,

c. an interference mechanism normally operative to prevent operation of said primary alarm mechanism,

d. an actuatable door lock mechanism operatively associated with said enclosure door,

e. means operative to automatically deactuate said door lock mechanism and unlock said enclosure door after a predetermined time has elapsed from actuation of said lock mechanism,

sensing means for sensing whether or not said enclosure door is closed,

g. control means operatively coupled to said interference mechanism, to said sensing means, to said door lock mechanism and to said primary alarm mechanism effective when operated to disable said interference mechanism and permit actuation of said primary alarm mechanism responsive to sensing by said sensing means that said enclosure door is closed, and to normally actuate said door lock mechanism to lock said enclosure door when said primary alarm mechanism is actuated.

2. A system as described in claim 1 wherein said door lock mechanism includes electrically actuatable means to lock said door, wherein said sensing means comprises electrical switch means having contacts which are opened or closed as determined by the open or closed state of said door, and wherein said control means comprises electrical switch means in electrical circuit with said door lock mechanism electrically actuatable means and with said sensing means electrical switch means.

3. A system as described in claim 2 wherein said sensing means electrical switch means comprises a first switch whose contacts are closes when said enclosure door is not closed, wherein said control means comprises electrically energizable means in electric circuit with said first switch and operatively coupled to said interference mechanism, whereby, said control means electrically energizable means when energized through the closed contacts of said first switch maintains said interference mechanism operative to prevent operation of said primary alarm mechanism, and when deenergized by opening of the contacts of said first switch when said enclosure door is closed renders said interference mechanism inoperative to permit operation of said primary alarm circuit.

4. A system as described in claim 3 wherein said sens ing means electrical switch means in electrical circuit with said control means electrical switch means comprises a second switch whose contacts are open when said enclosure door is not closed.

5. A system as described in claim 4 wherein said door lock mechanism is electrically actuatable and is mechanically deactuatable.

6. A system as described in claim 4 further including an actuatable secondary alarm mechanism operatively coupled to said control means, said secondary alarm mechanism being normally actuated by said control means when the latter actuates said primary alarm mechanism. 

1. A personnel detention system for holding captive a person who actuates an alarm circuit, comprising in combination, a. a primary alarm mechanism having an actuator, b. an enclosure within which said primary alarm mechanism is mounted, said enclosure having a door through which a person desiring to actuate said alarm may pass, and said enclosure having no other means of ingress or egress, c. an interference mechanism normally operative to prevent operation of said primary alarm mechanism, d. an actuatable door lock mechanism operatively associated with said enclosure door, e. means operative to automatically deactuate said door lock mechanism and unlock said enclosure door after a predetermined time has elapsed from actuation of said lock mechanism, f. sensing means for sensing whether or not said enclosure door is closed, g. control means operatively coupled to said interference mechanism, to said sensing means, to said door lock mechanism and to said primary alarm mechanism effective when operated to disable said interference mechanism and permit actuation of said primary alarm mechanism responsive to sensing by said sensing means that said enclosure door is closed, and to normally actuate said door lock mechanism to lock said enclosure door when said primary alarm mechanism is actuated.
 2. A system as described in claim 1 wherein said door lock mechanism includes electrically actuatable means to lock said door, wherein said sensing means comprises electrical switch means having contacts which are opened or closed as determined by the open or closed state of said door, and wherein said control means comprises electrical switch means in electrical circuit with said door lock mechanism electrically actuatable means and with said sensing means electrical switch means.
 3. A system as described in claim 2 wherein said sensing means electrical switch means comprises a first switch whose contacts are closes when said enclosure door is not closed, wherein said control means comprises electrically energizable means in electric circuit with said first switch and operatively coupled to said interference mechanism, whereby, said control means electrically energizable means when energized through the closed contacts of said first switch maintains said interference mechanism operative to prevent operation of said primary alarm mechanism, and when deenergized by opening of the contacts of said first switch when said enclosure door is closed renders said interference mechanism inoperative to permit operation of said primary alarm circuit.
 4. A system as described in claim 3 wherein said sensing means electrical switch means in electrical circuit with said control means electrical switch means comprises a second switch whose contacts are open when said enclosure door is not closed.
 5. A system as described in claim 4 wherein said door lock mechanism is electrically actuatable and is mechanically deactuatable.
 6. A system as described in claim 4 further including an actuatable secondary alarm mechanism operatively coupled to said control means, said secondary alarm mechanism being normally actuated by said control means when the latter actuates said primary alarm mechanism. 